Fire-bowl for furnaces and the like



W. R. LITZENBERG. FIRE BOWL FR FURNACES AND THE LIKE.

APPLlcArloN man Nov. a, 1915. nENEwED1uNf|,|92o.

Patented Jan. 4, 1921.

2% 4 7 \o /mo al /8 5 w@ s l @y UNITED STATES PATENT OFFICE.

FIRE-BOWL FOR FURNACES AND THE LIKE.

Specication of Letters Patent.

Patented Jan. 4L, 1921.

Application filed November 8, 1915, Serial No. 60,290. Renewed June i, 1920. Serial No. 385,795.

T0 @ZZ 'whom it may concern:

Be it known that I, WILLIAM R. LITZEN- BERG, a citizen of the United States, residing in the city of Portland, county of Multnomah and State of Oregon, have invented certain new and useful Improvements in Fire-Bowls for Furnaces and the like, of which the following is a specification.

My invention relates to improvements in fire bowls for use in stoves, furnaces, and other heating plants, and has among its salient obj ects,-to provide in the wall of a. iire bowl a series of inwardly opening air channels, or passageways, extending upwardly from the bottom of the bowl, so that air from the ash pit can pass freely upwardly through these air channels, or passageways, and thereby cause combustion of the fuel resting next against the sides of the fire bowl, and over these air channels, thus increasing the heat imparted directly to the walls of said fire bowl; to provide a fire bowl of the character referred to of outwardly flaring form, so that the air passing upwardly around the outside of said fire bowl must come more directly in contact therewith and be deflected outwardly in its upward course, and thereby be heated to a greater degree than when passing upwardly around a re bowl whose walls are substantially vertical.

VI have found in burning carbon briquets and other small fuel which burns up without any clinkers and with very little or no ash, that a smaller grate area can be used to better advantage than a large grate, for the reason that a small amount of fuel is piled more and therefore burns more readily than when it is spread out in a thin layer, and Ihave conceived the idea of not only thus reducing the grate area in the fire bowl, but of changing the shape of the fire bowl so that it is proportionately smaller at the bottom and flares outwardly toward its top, thus making it a more efiicient air heating device. By placing a tubular member over the middle of the grate, I not only save the fuel which would otherwise occupy the middle portion of the grate, but it forms a means for causing a column of air to rise from the Vash pit and to be heated and discharged within the combustion chamber. By forming comparatively narrow inwardly opening channels in the wall of the fire bowl, said channels being such that the fuel next thereto will bridge the same and will not ill or clog them, the warm air passing upwardly from the ash pit through these air channels will cause the combustion of the fuel resting directly against the side of the fire bowl, and will therefore more etliciently heat it, than when the combustion takes place more centrally of the fire bowl, by reason of the passing of the air up through the whole body of the fuel resting upon the iire grate. Inasmuch as carbon briquets require very little draft to keep them aglow after they have once been ignited, I have provided means for shutting off the draft directly through the grate, so that any air passing upwardly from the ash pit must pass through the air channels in the wall, or through the tubular hot air con-` duit in the middle of the fire bowl. In forming the air channels in the inside-of the wall of the fire bowl, there are formed corresponding ribs on the outside vof the fire bowl which increases the heating Vsurface area of the fire bowl, but this has been acw complished before by making the fire bowls of corrugated form.

In order that others may more clearly understand my invention, I have illustrated one practical embodiment thereof in the accompanying sheet of drawings, which I will now describe. f l

Figure 1 is a vertical sectional view through a fire bowl embodying my invention, a portion thereof being shown in side elevation, said view being taken in the posi.- tion of line 1 1 on Fig. 2; y

Fig. 2 is a fragmentary top plan view of the same;

` Fig. 3 is a bottom plan view of a grate adapted for use in my fire bowl;

Fig. 4 is a modified form of tubular member for use with the grate, instead of the member shown in Fig. 1; and

. Fig. 5 is a vertical sectional view through a complete furnace embodying my invention.` v

Referring now more in detailfto the drawings, and particularly to Figs. l and 2, l designates a preferred form of my iire bowl, which is shown to be of comparatively small diameter at its bottom and of compara'- tively large diameter at its top, its -side'wall flaring outwardly andupwardly in the manner indicated. The walls are formed so as to provide therein narrow, inwardly opening channels 2, extending from the lower edge of said wall to the upper edge thereof, whereby to form air passageways, or conduits. The formation of these inwardly opening channels on the inside of said fire bowl also forms the ribs 3, on the outside thereof, as clearly indicated at the left hand side of Fig. 1, thus increasing the outside heating surface. Formed in the bottom of said fire bowl 1, is an annular supporting ring 4f, upon which is mounted a grate 5. The grate here shown has an open center through which is mounted the lower end of a tubular member 6, having a aring annular flange 6, adapted to rest upon the top of the grate 5. Mounted upon the lower end of said tubular member 6, immediately underneath the grate 5, is a grate ring 7, shown in bottom plan view in Fig. 3, which grate ring 'in the present construction is sup ported by means of a collar 8, mounted thereunder upon the lower end of the tubular member 6, and secured thereto by means of a bolt 9. Said grate ring 7, is adapted to be turned slightly in either direction for the purpose of closing the openings through the grate 5, and to this end said grate ring 7, is provided with a handle 7a, as shown in Fig. 3. When the grate ring 7, is turned so as to close the grate 5, it will be evident that air can pass upwardly from the ash pit only through the air channels 2, or through the tubular member 6.

Detachably mounted in the upper end of said tubular member 6, is a deflector 10, shown in section in Figs. 1 and 5, adapted to defiect the air passing upwardly in the tubular member 6, downwardly and outwardly on to the fuel in the fire bowl around the outside of the tubular member 6.

The usual ash pit, of course, is directly underneath the grate and within the box which supports the fire bowl, this being indicated clearly in Fig. 5, within which are placed the reference numerals 5, 6 and 7, in said Fig. 5.

The air channels 2, formed on the inside ofthe fire bowl, communicate at their lower ends, outside the grate 5, with the ash pit below, so that air from the ash pit passes upwardly, not only through the tubular member 6, but through said air channels 2, as clearly indicated by the arrows in Fig. 5.

The ash pit, of course, is of usual construction, having the usual draft openings. As this forms no part of the present invention and is well understood, it is not necessary to illustrate any particular form of ash pit door.

My fire bowl is particularly well adapted for burning briquets and other small fuel which burns up completely, with little or no ash. The carbon briquets, for example,

when once ignited, remain red hot for a long time Aand until completely consumed with very little draft, and one of the principal objects of my invention is to provide a fire bowl having the inwardly opening air "channels, or conduits, in its side over which the fuel will rest, said air channels being such that the fuel will not enter them or cause them to be filled up. The air passing upwardly through these air channels causes a combustion of the fuel next adjacent the side or wall of the fire bowl, and thereby more directly heats it, said wall being in effect a sort of vertical or side grate, and inasmuch as the fire bowl iiares outwardly and upwardly, in the manner indicated, the air passing upwardly around the same must directly contact the outside of the fire bowl and be deflected outwardly in its upward passage, as indicated by the arrows in Fig. 5. This will more intensely heat the air than when it passes upwardly simply through radiated heat from a fire bowl whose sides are vertical, or substantially so, as is the case in most furnaces and stoves now in use.

In Fig. l I have shown a cone-shaped member 11, partly in side elevation and partly in section, adapted to be substituted for the tubular member 6, shown in Fig. 1, the lower end of this cone-shaped member 11, being the same as the lower end of the tubular member 6, and adapted to be attached to the grate and grate ring in exactly the same manner as is the tubular member 6.

This cone-shaped member is open at its top, as is clear from the drawing, so that air can pass upwardly therethrough in the same manner as it passes through the long tubular member 6.

It will be evident that my fire bowl can be cast in any size, and that it can be substituted for fire bowls now in use in furnaces of other makes, if desired, or it can be embodied in a complete furnace, as shown in Fig. 5, in which there is mounted over the fire bowl 1, a top, or dome, member D, having an annular air space, as 12, formed around its middle portion, communicating with the smoke flue 13, and having at its opposite side an outlet 14, for the gases and products of combustion, with a deflector, or baliie, plate 15, adjacent said outlet opening 14. This construction and its purpose, of course, will be readily understood from the drawings. The cold air is admitted through a pipe 16, passes upwardly around the fire bowl 1, as indicated by the arrows, and in order to deflect the air toward the center and over the dome portion of the fire bowl, I have also provided the sheet metal closure 17, of the furnace, with an annular, inwardly projecting deflector 18.

I do not limit my invention, of course, to the particular details here shown for purposes of illustrating the same, except as I may be limited by the hereto appended claims.

I claim:

1. In a hot air furnace, the combination with a casing of a fire bowl located therein and having in its inner face air channels extending from the bottom thereof upwardly, a grate at the lower end of the bowl, said bowl being relatively narrow at its bottom and greatly increasing in width and gradually curving outwardly from the bottom toward its upper portion so that the upper portion of the bowl is disposed at a pronounced angle to the bottom thereof, means for conveying air to the casing whereby the same contacts with the lower surface of the bowl and passes upwardly over its entire surface to intensely heat the air prior to its discharge from the casing, substantially as described.

2. In a hot air furnace, the combination with a casing, of a re bowl having a suitable grate disposed within the casing, said bowl being relatively narrow at its bottom and greatly increasing in width and gradually flaring outwardly from the bottom toward its upper portion so that the upper portion of the bowl is disposed at a pronounced angle to the bottom thereof, means for feeding air to the interior of the casing whereby the lower surface of the bowl dciiects the incoming air and directs the same upwardly over the flaring surface thereof throughout the length of the bowl to intensely heat the air prior to its discharge from the casing, substantially as described.

3. In a hot air furnace, the combination with a casing, of a fire bowl located therein and having in its inner face air channels extending from the bottom thereof upwardly, a grate at the lower end of the bowl, said bowl being relatively narrow at its bottom and greatly increasing in width and gradually curving outwardly from the bottom toward its upper portion so that the upper portion of the bowl is disposed at a pronounced angle to the bottom thereof, a fuel spacing element centrally of said grate, and means for conveying air to the casing whereby the same contacts with the lower surface of the bowl and passes upwardly over its entire surface to intensely heat the air prior to its discharge from the casing, substantially as described.

4. In a hot air furnace, the combination with a casing, of a fire bowl located therein and having in its inner face air channels extending from the bottom thereof upwardly, a grate at the lower end of the bowl, said bowl being relatively narrow at its bottom and greatly increasing in width and gradually curving outwardly from the bottom toward its upper portion so that the upperportion of the bowl is disposed at a pronounced angle to the bottom thereof, a tubular fuel spacing element` centrally of said grate and adapted to convey air from the ash box below the grate to the' combustion chamber above the fuel, and means for conveying air to the casing whereby the same contacts with the lower surface of the bowl and passes upwardly over its entire surface to intensely heat the air prior to its discharge from the casing, substantially as described.

5. In a hot air furnace, the combination with an outer casing, of a fire bowl located therein, said fire bowl being relatively narrow at its bottom and greatly increasing in width and gradually curving outwardly from the bottom toward its upper portion so that the upper portion of the bowl is disposed at a pronounced angle to the bottom thereof, means for conveying air to the casing whereby the same contacts with the lower surface of the bowl and passes up` wardly over its entire surface to intensely heat the air as it contacts therewith, and means within the bowl for directly heating the inside surface of said bowl, whereby the heat is more directly applied to the inside surface of the outwardly flaring fire bowl wall, and against the outside of which flaring fire bowl wall the air contacts.

Signed at Portland, Multnomah county, Oregon, this second day of November, 1915.

WILLIAM R. LITZENBERG.

In the presence of- I. M. GRIFFIN, WARREN P. SMITH. 

